Those little divices can open a lot of locks. If you find the right one you may be able to open any door. Keys are baring information and are often unique. The key is the answer to the puzzle set by the maker of a lock. This little object has even evolved into a powerful symbol of safekeeping of the things that are dearest to us. Keys were often used as a right of passage such as reaching adulthood and are part of the folklore in many cultures. Key is also the symbol of luck. The ancient Greeks used one key as a symbol for knowledge and life.